Google could give Motorola/HTC/etc a license to the patents.
But Motorola/HTC/etc could not use them to counter sue Microsoft or Apple if they also own the same patent.

Apple, Microsoft, etc would simply sue Motorola/HTC using other patents.

The only way the patents help Android is if Google/Motorola/HTC/etc can use them against Apple, Microsoft, Oracle.

Maybe if it spelled out you will get it.

Mutually Assured Destruction works like this:
If Google solely owned the patents:
MS to Moto: We will sue you for patent A
Moto to MS: We will counter sue you for B that Google licensed to us
MS and Moto agree not to bother one another.

If Google/MS both own the patents:
MS to Moto: We will sue you for patent A
Moto to MS: We will counter sue you for B that Google licensed to us
MS to Moto: We also own patent B, sorry but we own you!
Moto to MS: How much to license patent A?